1. Field of the Invention
The present invention relates to a weather strip for an automobile.
2. Description of the Prior Art
Description will be made of a conventionally used weather strip with reference to FIGS. 1 and 2. In FIG. 1, reference numeral O denotes the outside of an automobile body, and reference numeral I the inside of the automobile body. Reference numeral 21 denotes a door panel, and reference numeral 22 a body panel. Reference numeral 23 denotes an inner panel provided on the inside of the body panel 22. Reference numeral 24 denotes a flange portion in which the flanges of both the body panel 22 and the inner panel 23 are brought together and welded to each other. To the flange portion 24 is fitted a weather strip 26 having a retainer 29 with a U-shaped cross section as well as a hollow and cylindrically shaped sponge seal 25 on the outer side of the retainer 29 facing away from the flange.
A reinforcing core metal 27 is embedded inside the retainer 29, and a plurality of retainer lips are provided on the inner side of the retainer 29 in such a manner as to project therefrom and enhance its ability to grip the flange portion 24. The retainer 29 and the retainer lips 28 are formed integrally of solid rubber.
Incidentally, the weather strip 26 must meet two contradictory requirements in the sense that the force (inserting force) required to fit the weather strip 26 to the flange portion 24 should be small and the retaining force for opposing any withdrawal force applied after installation should be large.
To this end, each of the retainer lips 28 has conventionally been made into one 28a with a large thickness, as shown in FIG. 2. In such an arrangement, however, the space between the opposing surfaces of the retainer lips 28a expands, causing the sides of the retainer 29 to move apart. Consequently, various troubles can arise such as the installed weather strip 26 coming off the flange portion 24, and it thus becomes impossible to obtain the desired effects.